Preparation method for directly synthesizing titanium dioxide from titanium-rich organic phase prepared from ilmenite

A method for directly synthesizing titanium dioxide from a titanium-rich organic phase prepared from ilmenite, comprising the following steps:

• adding hydrochloric acid and ilmenite to a reactor to form a hydrochloric acid/ilmenite mixture having a mass ratio of 1-15:1, introducing a hydrogen chloride gas into the reactor, so that a pressure P in the reactor is higher than an atmospheric pressure, maintaining the reactor for reaction under stirring at a raised temperature T1 and the pressure P, after the reaction is completed, reducing the raised temperature T1, and adding an oxidizing agent thereto and stirring followed by filter-pressing to obtain a filtrate which is a hydrochloric acid solution A0 containing titanium and iron ions;
• adding the hydrochloric acid solution A0 into an iron extractor for a multi-stage extraction with an iron extractant, and combining extracts of the multi-stage extraction as organic phases to obtain an iron-rich extraction liquid, which is an organic phase A1, wherein an aqueous phase obtained from the multi-stage extraction is an iron ion-free titanium-containing raffinate, which is an aqueous phase B1;
• adding the iron-rich extraction liquid into an iron backwash extractor, and back-extracting iron ions with an iron back extractant to obtain an organic phase A2 and a raffinate B2 as a ferric chloride-containing aqueous phase;
• adding the iron ion-free titanium-containing raffinate to a purification extractor, and then carrying out multi-step purification with a purification extractant to remove colored ions so as to obtain an aqueous titanium-enriched raffinate C1;
• and
• adding the aqueous titanium-enriched raffinate C1 to a titanium extractor, extracting the aqueous titanium-enriched raffinate C1 with a titanium extractant to obtain an organic phase C2 containing high-purity titanium ions;
• causing organic phase C2 to enter a titanium dioxide synthesis reactor directly, adding a precipitant into the titanium dioxide synthesis reactor to prepare a titanium precipitate, and obtaining the titanium dioxide from the titanium precipitate.